Method of manufacturing microlens, microlens, microlens array plate, electrooptic device and electronic equipment

ABSTRACT

A method of manufacturing a microlens includes: forming on a transparent substrate a first film which has an etching rate higher than the transparent substrate, forming on the first film a mask in which a pit is provided at a position corresponding to a center of the microlens to-be-formed, and wet-etching the first film and the transparent substrate through the mask, to thereby excavate in the transparent substrate a non-spherical recess which defines a curved surface of the microlens.

BACKGROUND OF THE INVENTION

[0001] 1. Field of Invention

[0002] The present invention relates to a method of manufacturing amicrolens which constitutes, for example, a microlens array plate suitedfor application to an electrooptic device, such as a liquid crystaldevice. The invention further relates to a microlens manufactured by themanufacturing method, a microlens array plate, an electrooptic deviceincluding the microlens, and an electronic equipment including theelectrooptic device.

[0003] 2. Description of Related Art

[0004] In a related art electrooptic device, such as a liquid crystaldevice, various wiring lines, such as data lines, scanning lines andcapacitance lines, and various electronic elements, such as thin filmtransistors (hereinbelow “TFTs”) or thin film diodes (hereinbelow“TFDs”), are formed within an image display area. In each pixel,therefore, a region through or from which light capable of actuallycontributing to display is transmitted or reflected is essentiallylimited due to the existence of the various wiring lines and electronicelements, etc. Specifically, regarding each pixel, the opening rate ofeach pixel as is the rate of a region through or from which lightactually contributing to display is transmitted or reflected (that is,the aperture region of each pixel), to the whole region, is about70%,for example. Illumination source light or external light which isentered into the electrooptic device mostly includes parallel lightrays, at least, when passing through an electrooptic substance layer,such as a liquid crystal layer, within the electrooptic device. However,in a case where parallel light rays have been entered into theelectrooptic device, only that part of the whole quantity of light whichis proportional to the opening rate of each pixel can be utilizedwithout any contrivance.

[0005] Therefore, in the related art, a microlens array which includesmicrolenses corresponding to the respective pixels can be formed in anopposite substrate, or a microlens array plate can be stuck on anopposite substrate. Due to such microlenses, light rays which ought toprogress toward the non-aperture regions of the respective pixels exceptthe aperture regions thereof without the microlenses are collected inpixel units, so as to be guided into the aperture regions of therespective pixels when they are transmitted through the electroopticsubstance layer. As a result, a bright display is realized by utilizingthe microlens array in the electrooptic device.

[0006] The manufacture of this type of related art microlens is providedas stated below. First, a mask which is provided with a pit at aposition corresponding to the center of the microlens to be formed isformed on, for example, a transparent substrate. Subsequently, thetransparent substrate is subjected to wet etching through the mask, tothereby excavate a spherical recess which defines the curved surface ofthe microlens. Thereafter, the mask is removed, and the recess is filledup with a transparent medium of high refractivity. Thus, the microlensis formed in which a hemispherical recess centering around the pithaving been first provided in the mask is included as a lens sphericalsurface. The microlens array can be manufactured by forming a largenumber of such microlenses in the shape of an array.

[0007] In the case of this type of microlens, it is important as basicrequirements to enhance a lens efficiency and further to diminishspherical aberration.

[0008] According to the related art method of manufacturing themicrolens as stated above, however, a non-spherical lens cannot bemanufactured, although a spherical lens can be manufactured,comparatively easily.

[0009] In this regard, in order to manufacture the non-spherical lens,the related art includes a complicated and high-degree manufacturingmethod, for example, one in which a non-spherical recess is formed froma separate material on a substrate and is thereafter transferred ontothe side of the substrate, or one in which a substrate is subjected to aplurality of different etching steps stage by stage. Such amanufacturing method, however, is basically difficult and increasesmanufacturing costs as well as reduces an available percentage. Further,there occurs the problem that, as manufacturing steps become complicatedand high in degree, controlling the degree of non-sphericalness in thenon-spherical lens becomes technically very difficult.

SUMMARY OF THE INVENTION

[0010] The present invention addresses or solves the above and/or otherproblems, and provides a method of manufacturing a microlens that iscapable of manufacturing the non-spherical microlens comparativelyeasily. The invention also provides the microlens which is manufacturedby the manufacturing method, an electrooptic device which includes themicrolens, and an electronic equipment which includes the electroopticdevice.

[0011] In order to address or solve the above, a method of manufacturinga microlens according to the present invention includes: forming on asubstrate a first film an etching rate of which for a predetermined kindof etchant differs from that of the substrate; forming on the first filma mask in which a pit is provided at a position corresponding to acenter of the microlens to-be-formed; and performing wet etching throughthe mask, to thereby excavate in the substrate a non-spherical recesswhich defines a curved surface of the microlens.

[0012] In accordance with the method of manufacturing a microlensaccording to the present invention, first of all, the substrate, forexample, a quartz substrate or a glass substrate is formed thereon withthe first film the etching rate of which for the predetermined kind ofetchant, for example, one of hydrofluoric acid type differs from that ofthe substrate. Such a first film is formed by, for example, CVD(Chemical Vapor Deposition) or sputtering. Subsequently, the mask inwhich the pit is provided at the position corresponding to the center ofthe microlens to-be-formed is formed on the first film. Such a mask maywell be formed in such a way, for example, that a second film is formedon one surface of the first film by CVD, sputtering or the like,whereupon it is patterned by photolithography and etching so as toprovide the pit. Alternatively, the mask may well be formed directly onthe region of the first film except the pit. Thereafter, the first filmand the substrate are wet-etched through such a mask. The etching ratesfor the etchant employed here differ from each other between the firstfilm and the substrate. Therefore, before the etching penetrates throughthe first film, a spherical recess is excavated in the part of the firstfilm around the pit, by the wet etching which has no directionality.After the penetration, however, a non-spherical recess is excavatedbecause the degree to which the first film is etched and the degree towhich the substrate is etched are different from each other.

[0013] Thereafter, the non-spherical microlens can be manufacturedcomparatively easily by utilizing the curved surface which thenon-spherical recess thus excavated defines. By way of example, it ispermitted to manufacture the non-spherical micro lens by making thesubstrate a transparent one and filling up the recess with a transparentmedium. Alternatively, it is permitted to manufacture the non-sphericalmicrolens by utilizing the recess as a mold. Further, it is permitted tomanufacture the microlens being a biconvex lens, by preparing twosubstrates, each of which is formed with such a microlens, and thensticking them to each other.

[0014] In an aspect of the method of manufacturing a microlens accordingto the present invention, the first film is higher in the etching ratethan the substrate.

[0015] In accordance with this aspect, due to the etching, the recess inthe shape of a pan whose bottom is shallower than a hemisphere isexcavated in the substrate unlike in the first film which is higher inthe etching rate than the substrate.

[0016] In another aspect of the method of manufacturing a microlensaccording to the present invention, the substrate is made of atransparent substrate; and the step of putting into the recess atransparent medium which has a refractivity higher than that of thetransparent substrate is further provided.

[0017] According to this aspect, the transparent medium the refractivityof which is higher than the transparent substrate is put into the recesswhich is excavated in the substrate made of the transparent substrate,and hence, it is permitted to manufacture the microlens as anon-spherical convex lens on the transparent substrate. On thisoccasion, the transparent medium is made of a transparent resin or thelike, and it may well serve as an adhesive. By way of example, it maywell serve as the adhesive in the case of sticking a cover glass ontothe transparent substrate.

[0018] The transparent substrate can also be made of a quartz, forexample. In this case, advantageously the quartz substrate is notdestroyed even when exposed to high temperatures in forming the firstfilm. However, in a case where the first film is formed at a lowtemperature, refractoriness is not required of the transparentsubstrate. The transparent substrate may be, for example, a glass plateor a plastic or resin plate. No problem occurs as long as thetransparent substrate is made of a substance which can be etched by thepredetermined kind of etchant together with the first film.

[0019] In the case where the recess excavated in the substrate isemployed as the mold of the microlens, the substrate need not betransparent.

[0020] In another aspect of the method of manufacturing a microlensaccording to the present invention, the first film is made of atransparent film or an opaque film.

[0021] In accordance with this aspect, even when the first film is leftintact around the recess after the recess has been excavated by theetching, an optical performance concerning the microlens undergoesalmost no, or substantially no, negative influence by constructing thefirst film out of the transparent film. Further, the vicinity of theedge of the recess as is made of the first film can also be employed asthe vicinity of the edge of the non-spherical lens.

[0022] However, the first film part left around the recess lies at theedge of the optical path of light which is collected by the microlens,so that even when the first film is formed of a semitransparent film orthe opaque film, a bad influence which is exerted on the opticalperformance concerning the microlens is limited.

[0023] In another aspect of the method of manufacturing a microlensaccording to the present invention, the first film is made of a siliconoxide film or a silicon nitride film.

[0024] In accordance with this aspect, the first film which has theetching rate different from that of the substrate can be formedcomparatively easily. By way of example, the silicon oxide film whosethickness and quality are stable can be formed on the quartz substratecomparatively easily by CVD or sputtering. Moreover, the first filmwhich is transparent as in the above aspect can be formed of the siliconoxide film.

[0025] In another aspect of the method of manufacturing a microlensaccording to the present invention, the etching rate is controlled bycondition setting which concern at least one of a sort of the firstfilm, a method of forming the first film, a condition to form the firstfilm, and a temperature of a heat treatment after the formation of thefirst film.

[0026] In accordance with this aspect, the etching rate is controlled bythe condition setting which concerns at least one of the sort of thefirst film relating to, for example, a substance, a density and aporosity; forming the first film, for example, CVD or sputtering; thetemperature to form the first film, for example, one below about 400° C.or one of about 400-1000° C.; and the temperature of the heat treatmentafter the formation of the first film. Besides, due to such a control ofthe etching rate, a curvature or a curvature distribution in anon-spherical surface which the recess to be finally obtained definescan be controlled comparatively easily. The curvature or the curvaturedistribution in the non-spherical surface which the recess to be finallyobtained defines can also be controlled by the thickness of the firstfilm.

[0027] In another aspect of the method of manufacturing a microlensaccording to the present invention, the mask is made of a poly-siliconfilm, an amorphous silicon film or a hydrofluoric acid-proof film.

[0028] In accordance with this aspect, the mask in which the pit isprovided at the predetermined position can be formed on the first filmmade of, for example, the silicon oxide film, comparatively easily by,for example, the CVD or the sputtering.

[0029] In another aspect of the method of manufacturing a microlensaccording to the present invention, a plurality of such microlenses areformed in the shape of an array on the substrate.

[0030] In accordance with this aspect, a microlens array is manufacturedin which a plurality of non-spherical microlenses as stated above areformed in the shape of the array. Therefore, the microlens array whichis well suited for application to, for example, an electrooptic devicewhere pixels are arrayed in the shape of an array or a matrix can bemanufactured comparatively easily.

[0031] In order to address or solve the above, a microlens according tothe present invention is manufactured by the method of manufacturing amicrolens according to the present invention as stated above (includingthe various aspects thereof).

[0032] The microlens according to the present invention is manufacturedby the method of manufacturing a microlens according to the presentinvention as stated above, so that it can collect illumination sourcelight, external light, etc. with a slight spherical aberration and at ahigh efficiency, and it can realize the microlens, and further amicrolens array or a microlens array plate, which are easilymanufactured, which are comparatively inexpensive and whose qualitiesare stable.

[0033] In a case where the microlens according to the present inventionis formed directly on the substrate, it has the structural featurepeculiar to the present invention, that the boundary between the firstfilm and the substrate exists in the vicinity of the edge of the lenscurved surface being non-spherical and that the curvature of the lenscurved surface changes remarkably at the boundary. Alternatively, in acase where the microlens according to the present invention is formedthrough a mold by the 2 P method or the like, it has the structuralfeature peculiar to the present invention, that the curvature of thelens curved surface changes remarkably at a position which correspondsto the boundary between the first film and the substrate in the vicinityof the edge of the lens curved surface being non-spherical.

[0034] A microlens array plate according to the present inventionincludes a large number of microlenses; a transparent member which hasconcavities that define bottoms of the microlenses; a film which isformed on the transparent member, and which has pits that are formed incorrespondence with the concavities and that define edges of themicrolenses; and a cover member which is formed on the film. Thesectional shape of each of the microlenses is semi-elliptical.

[0035] A microlens array plate according to the present invention shouldpreferably be provided such that a sectional shape in the vicinity of aregion featuring an angle of 50-60 degrees, which a tangential line to alens surface in the film forms with respect to a tangential line to anedge of a lens surface defined by the transparent member, issemielliptical.

[0036] A microlens array plate according to the present invention shouldpreferably be provided such that a sectional shape of the lens surfacein the film is rectilinear.

[0037] In order to address or solve the above, an electrooptic deviceaccording to the present invention includes the microlens according tothe present invention as stated above; a displaying electrode whichopposes the microlens; and a wiring line or an electronic element whichis connected to the displaying electrode.

[0038] The electrooptic device according to the present inventionincludes the microlens according to the present invention as statedabove, so that it can collect illumination source light, external light,etc. with a slight spherical aberration and at a high efficiency by thenon-spherical microlens, and it can realize the electrooptic devicewhich is capable of displaying a bright and vivid image. Such anelectrooptic device can be constructed as a liquid crystal device ofactive matrix drive type or the like electrooptic device in which thewiring lines, such as scanning lines and data lines, and the electronicelements, such as TFTs or TFDs, are connected to the displayingelectrodes, such as insular pixel electrodes or stripe-shapedelectrodes.

[0039] In order to address or solve the above, an electronic equipmentaccording to the present invention includes the electrooptic deviceaccording to the present invention as stated above.

[0040] The electronic equipment according to the present inventionincludes the electrooptic device according to the present invention asstated above, so that it can realize various operations, such as thoseof a projector, a liquid crystal TV receiver, a portable telephone, anelectronic notebook, a word processor, a video tape recorder of viewfinder type or monitor direct view type, a workstation, a videotelephone, a POS terminal and a touch panel, for example, which arebright and which have excellent display qualities.

[0041] Such operations and other advantages of the present inventionwill be clarified by exemplary embodiments described below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0042]FIG. 1 is a schematic perspective view of an exemplary embodimentconcerning the microlens array plate of the present invention;

[0043]FIG. 2 is a partial enlarged plan view showing on an enlargedscale a part which concerns four microlenses in the exemplary embodimentconcerning the microlens array plate;

[0044]FIG. 3 is a partial enlarged sectional view of the exemplaryembodiment concerning the microlens array plate;

[0045]FIG. 4 is a partial enlarged sectional view further showing on anenlarged scale a part which concerns one microlens in the exemplaryembodiment concerning the microlens array plate;

[0046]FIG. 5 is a partial enlarged sectional view in a modifiedexemplary embodiment of the microlens array plate of the presentinvention;

[0047]FIG. 6 is a plan view in which a TFT array substrate and variousconstituents formed thereon in an exemplary embodiment concerning theelectrooptic device of the present invention are viewed from the side ofan opposite substrate;

[0048]FIG. 7 is a sectional view taken along plane H-H′ in FIG. 6;

[0049]FIG. 8 is a schematic showing an equivalent circuit of severaltypes of elements, wiring lines, etc. disposed for a plurality ofmatrix-shaped pixels which constitute an image display area in theexemplary embodiment concerning the electrooptic device;

[0050]FIG. 9 is a plan view of a plurality of pixel groups adjacent toeach other, on a TFT array substrate which is formed with data lines,scanning lines, pixel electrodes, etc. in the exemplary embodimentconcerning the electrooptic device;

[0051]FIG. 10 is a sectional view taken along plane A-A′ in FIG. 9;

[0052]FIG. 11 is a sectional view schematically showing a situationwhere incident light rays are collected by each microlens of themicrolens array plate used as an opposite substrate, in the exemplaryembodiment concerning the electrooptic device;

[0053] FIGS. 12(a)-12(f) are schematics showing processing steps of amethod of manufacturing the microlens array plate; and

[0054]FIG. 13 is a schematic sectional view showing a colorliquid-crystal projector which is one example of a multiple-plate typecolor projector in accordance with an exemplary embodiment of theelectronic equipment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0055] Exemplary embodiments of the present invention are describedbelow with reference to the drawings.

[0056] (Microlens array plate)

[0057] First, a microlens array plate which can be manufactured by amethod of manufacturing a microlens according to the present inventionis described below with reference to FIGS. 1 through 5. FIG. 1 is aschematic perspective view of a microlens array plate, FIG. 2 is apartial enlarged plan view showing on an enlarged scale a part whichconcerns four microlenses in the microlens array plate of this exemplaryembodiment, FIG. 3 is a partial enlarged sectional view of the microlensarray plate of this exemplary embodiment, and FIG. 4 is a partialenlarged sectional view further showing on an enlarged scale a partwhich concerns one microlens. FIG. 5 is a partial enlarged sectionalview of a microlens array plate in a modified exemplary embodiment.

[0058] As shown in FIG. 1, the microlens array plate 20 of thisexemplary embodiment includes a transparent plate member 210 which ismade of, for example, a quartz plate, and which is covered with a coverglass 200. In the transparent plate member 210, a large number ofconcavities are excavated in the shape of a matrix. Besides, theconcavities are filled up with transparent bonding layers 230 which bondthe cover glass 200 and the transparent plate member 210 to each other,which are formed by hardening an adhesive made of, for example, aphotosensitive resin material, and which have a refractivity higher thanthat of the transparent plate member 210. A large number of microlenses500 which are planarly arrayed in the shape of the matrix, areconstructed of these constituents.

[0059] In this manner, in this exemplary embodiment, one example of a“substrate” according to the present invention is constructed of thetransparent plate member 210, and one example of a “transparent medium”according to the present invention is constructed of the bonding layer230.

[0060] As shown in FIGS. 2 and 3, the curved surface of each microlens500 is significantly or mainly defined by the transparent plate member210 and the bonding layer 230 whose refractivities are different fromeach other. Besides, each microlens 500 is constructed as a convex lenswhich protrudes downwards as viewed in FIG. 3.

[0061] In this exemplary embodiment, the microlens array plate ismanufactured especially by the manufacturing method peculiar to thepresent invention as stated below, and hence, a first film 220 is leftin the vicinity of the edge of each microlens 500, as well as on theupper surface of that region of the transparent plate member 210 inwhich the microlens 500 is not formed. The first film 220 is made of,for example, a transparent silicon oxide film, and it lies in closecontact with the cover glass 200 through the adhesive layer 230.

[0062] The microlens array plate 20 has each microlense 500 arranged sothat, in the use of this plate, they may correspond to the respectivepixels of the electrooptic device, for example, the liquid crystaldevice to be described later. Accordingly, incident light rays enteringinto the central part of each microlens 500 are collected toward thecenter of the corresponding pixel in the electrooptic device by therefraction of each microlens 500.

[0063] As shown in FIGS. 3 and 4, at the edge part of each microlens500, the curved surface thereof rises abruptly relative to the plane ofthe cover glass 200 or the plane of the transparent plate member 210.Here, especially the edge part of each microlens 500 is formed of thefirst film 220 the etching rate of which differs from that of thetransparent plate member 210.

[0064] As shown in FIG. 4, the microlens 500 is generally formed into asemielliptical section. Specifically, a lens curved surface in thetransparent plate member 210 is a pan-like non-spherical surface whosebottom is shallower than a spherical surface, that is, it issemielliptical in section. Moreover, a lens curved surface in the firstfilm 220 rises more abruptly than such a pan-like non-spherical surface.That is, it is rectilinear in section. In each microlens 500,accordingly, the radius of curvature in the vicinity of the centerbecomes larger than in case of a spherical lens. A lens efficiency isenhanced in accordance with the degree of such a non-spherical surface.Further, spherical aberration diminishes, and a focal point becomes aspredetermined more than in the case of the spherical lens.

[0065] In addition, as shown in FIG. 4, the lens curved surface isdefined so that a tangential line Lt2 to the upper edge of the mostinclined part in the first film 220, namely, the part of the lens curvedsurface made of the first film 220, may form an angle of, for example,50-60 degrees with respect to a tangential line Lt1 to the upper edge ofthe most inclined part in the transparent plate member 210, namely, thepart of the lens curved surface made of the transparent plate member210. Accordingly, a much better lens efficiency can be attained, andirregular reflection light, etc. can be more effectively prevented fromappearing, than in a case where the lens curved surface is definedgentle so as to form an angle of, for example, about 30-40 degrees, orin a case where the lens curved surface is defined abrupt so as to forman angle of, for example, about 70-80 degrees.

[0066] The angle which is formed by the tangential lines Lt1 and Lt2 isappropriately set in conformity with the specifications of theelectrooptic device, whereby incident light rays collected through, notonly the vicinity of the center of each microlens 500, but also thevicinity of the edge thereof, can be passed through the aperture regionof the corresponding pixel when they are transmitted through a liquidcrystal layer, etc. within the electrooptic device.

[0067] As the result of the above, incident light rays such as projectedlight rays entered from above as viewed in each of FIGS. 3 and 4 can beefficiently utilized as light rays contributing to display, by a lightcollection action based on each microlens 500 being the non-sphericallens. Simultaneously, owing to each microlens 500 being thenon-spherical lens, spherical aberration in the exit light rays thereofcan be reduced or mitigated. In consequence, a bright and vivid imagedisplay is finally realized.

[0068] Moreover, since the microlens array plate 500 of the presentinvention having the excellent lens characteristics in this manner ismanufactured by the manufacturing method of the present invention to bedescribed below, it is easy of manufacture, it is comparativelyinexpensive, and it attains a stable quality.

[0069] As shown in FIG. 5, as one modification to this exemplaryembodiment, a microlens array plate 20 may be provided with light shieldfilms 240 defining, at least, parts of non-aperture regions in anelectrooptic device in which the microlens array plate 20 is mounted.More specicically, the light shield films 240 having a checkered planpattern may be constructed so as to solely define the checkerednon-aperture regions. Alternatively, the light shield films 240 havingstripe-shaped plan patterns may be constructed so as to define thecheckered non-aperture regions in cooperation with other light shieldfilms.

[0070] With the construction as shown in FIG. 5, the non-apertureregions of the respective pixels can be defined more reliably, and thelight leakage, etc. between the adjacent pixels can be avoided. Further,it is permitted to reliably prevent light from entering into electronicelements, such as TFTs or TFDs, which are formed in the non-apertureregions of the electrooptic device, and in each of which the entrance ofthe light generates a light leakage current based on a photoelectriceffect, to thereby change characteristics.

[0071] In FIG. 5, the light shield films 240 are overlaid with aprotective film 241. Further, a counterelectrode or an orientation filmas described later may be formed instead of, or in addition, to theprotective film 241.

[0072] In the microlens array plate as shown in FIG. 5, a color filterof R (red), G (green) or B (blue) can be formed in the aperture regionof each pixel partitioned by the light shield films 240.

[0073] (Electrooptic device)

[0074] Next, the entire construction of an exemplary embodimentconcerning the electrooptic device of the present invention is describedbelow with reference to FIGS. 6 and 7. An exemplary liquid crystaldevice of a TFT active matrix drive scheme having built-in drivercircuits is shown as one example of the electrooptic device.

[0075]FIG. 6 is a plan view in which a TFT array substrate and variousconstituents formed thereon are seen from the side of the foregoingmicrolens array plate for use as an opposite substrate, while FIG. 7 isa sectional view taken along plane H-H′ in FIG. 6.

[0076] Referring to FIGS. 6 and 7, in the electrooptic device accordingto this exemplary embodiment, the TFT array substrate 10 and themicrolens array plate 20 for use as the opposite substrate are arrangedin opposition to each other. A liquid crystal layer 50 is enclosedbetween the TFT array substrate 10 and the microlens array plate 20,which are bonded to each other by a sealant 52 that is disposed in asealing region located around an image display area 10 a.

[0077] The sealant 52 is made of, for example, an ultraviolet-hardenableresin or a thermosetting resin to sticki both the substrates together,and the material is applied onto the TFT array substrate 10 and isthereafter hardened by ultraviolet radiation, heating or the like in amanufacturing process. A gap material, such as glass fiber or glassbeads, to set the spacing (inter-substrate gap) between the TFT arraysubstrate 10 and the microlens array plate 20 at a predetermined valueis dispersed in the sealant 52. That is, the electrooptic device of thisembodiment is suitable as a small-sized liquid crystal device whichpresents an enlarged display for the light valve of a projector.However, if the electrooptic device is a large-sized liquid crystaldevice presenting a full-size display, like a liquid crystal display ora liquid crystal TV receiver, such a gap material may be contained inthe liquid crystal layer 50.

[0078] A frame light-shield film 53 which intercepts light and whichdefines the frame region of the image display area 10 a, is provided onthe side of the microlens array plate 20 so as to extend inside and inparallel with the sealing region where the sealant 52 is arranged. Sucha frame light-shield film, however, may well be partly or entirelyprovided as a built-in light shield film on the side of the TFT arraysubstrate 10.

[0079] In a peripheral region within a region spreading around the imagedisplay area as is located outside the sealing region where the sealant52 is arranged, a data line driver circuit 101 and external circuitconnection terminals 102 are disposed along one latus of the TFT arraysubstrate 10, while scanning line driver circuits 104 are disposed alongtwo latera adjoining the above latus. Further, a plurality of wiringlines 105 to join the scanning line driver circuits 104 disposed on boththe sides of the image display area 10 a are laid along one remaininglatus of the TFT array substrate 10. Besides, as shown in FIG. 6,vertical conduction members 106 which function as the verticalconduction terminals between both the substrates are arranged at thefour corner parts of the microlens array plate 20. On the other hand,the TFT array substrate 10 is provided with vertical conductionterminals in its regions which oppose to the above corners,respectively. Due to the vertical conduction terminals, electricalconduction can be established between the TFT array substrate 10 and themicrolens array plate 20.

[0080] Referring to FIG. 7, the TFT array substrate 10 is formed with anorientation film on pixel electrodes 9 a after pixel switching TFTs andthe wiring lines, such as scanning lines and data lines, have beenformed. On the other hand, the microlens array plate 20 is overlaid witha counterelectrode 21, in addition to the cover glass 200, transparentplate member 210 and microlenses 500 described before, and further withan orientation film at an uppermost layer part (in FIG. 7, at the lowersurface of the microlens array plate 20). Besides, the liquid crystallayer 50 is made of a liquid crystal in which one kind or several kindsof nematic liquid crystal/crystals is/are mixed by way of example, andwhich assumes predetermined orientation states between the pair oforientation films.

[0081] The TFT array substrate 10 shown in FIGS. 6 and 7 may well beoverlaid with, not only the data line driver circuit 101, scanning linedriver circuits 104, etc., but also a sampling circuit which samplesimage signals on image signal lines and feed them to the data lines,precharge circuits which feed precharge signals of predetermined voltagelevel to the plurality of data lines before the feed of the imagesignals, respectively, an inspection circuit which serves to inspect thequality, defects, etc. of the electrooptic device midway of manufactureor at shipment, and so forth.

[0082] Next, a circuit arrangement and an operation in the electroopticdevice constructed as stated above is described below with reference toFIG. 8. FIG. 8 is a schematic showing an equivalent circuit of severaltypes of elements, wiring lines, etc. in a plurality of pixels which areformed in the shape of a matrix and which constitute the image displayarea of the electrooptic device.

[0083] Referring to FIG. 8, each of a plurality of pixels, whichconstitute the image display area of the electrooptic device in thisexemplary embodiment and which are formed in the shape of a matrix, isformed with a pixel electrode 9 a, and a TFT 30 for the switchingcontrol of the pixel electrode 9 a. Each data line 6 a which is fed withan image signal, is electrically connected to the sources of thecorresponding TFTs 30. Such image signals S1, S2, . . . , and Sn are fedto the respective data lines 6 a. The image signals S1, S2, , and Sn tobe written into the data lines 6 a in this manner may be fed in linesequence in this order, or they may well be fed to the plurality ofadjacent data lines 6 a every group.

[0084] Each scanning line 3 a is electrically connected to the gates ofthe pixel switching TFTs 30, and scanning signals G1, G2, . . . , and Gmare applied to the corresponding scanning lines 3 a pulse-wise atpredetermined timings and in line sequence in this order. The pixelelectrodes 9 a are electrically connected to the drains of thecorresponding TFTs 30, and they turn ON the TFTs 30 being switchingelements, for a predetermined time period, whereby the image signals S1,S2, . . . , and Sn fed from the data lines 6 a are respectively writtenat predetermined timings. The image signals S1, S2, . . . , and Sn ofpredetermined levels written through the pixel electrodes 9 a into aliquid crystal being one example of an electrooptic substance, arerespectively retained between the pixel electrodes 9 a and acounterelectrode formed in an opposite substrate, for a predeterminedtime period. The liquid crystal modulates light and permits agradational display in such a way that the orientation and order of itsmolecular aggregate are changed by the applied potential levels. In anormally-white mode, the transmission factor of the liquid crystal forentered light decreases in accordance with a voltage applied in eachindividual pixel unit, and in a normally-black mode, the transmissionfactor of the liquid crystal for entered light increases in accordancewith a voltage applied in each individual pixel unit, whereby lightwhich has a contrast conforming to the image signals exits from theelectrooptic device as a whole. Here, in order to prevent the retainedimage signal from leaking, a storage capacitor 70 is added in parallelwith a liquid crystal capacitance which is formed between the pixelelectrode 9 a and the counterelectrode. Each capacitance line 300 whichincludes the fixed potential side capacitor electrodes of the storagecapacitors 70 and which is fixed at a constant potential, is laid inparallel with the scanning line 3 a.

[0085] Next, a construction in the image display area of theelectrooptic device of the exemplary embodiment of the present inventionis described below with reference to FIGS. 9 and 10. FIG. 9 is a planview of a plurality of pixel groups adjacent to each other, on the TFTarray substrate which is formed with data lines, scanning lines, pixelelectrodes, etc. FIG. 10 is a sectional view taken along plane A-A′ inFIG. 9. In FIG. 10, individual layers and individual members haverespectively different reduced scales for the purpose of making themlarge enough to be more recognizable in the drawing.

[0086] Referring to FIG. 9, the plurality of transparent pixelelectrodes 9 a (whose contours are indicated by dotted line parts 9 a′)are disposed in the shape of a matrix on the TFT array substrate of theelectrooptic device, and the data lines 6 a and the scanning lines 3 aare respectively laid along the vertical and lateral boundaries of thepixel electrodes 9 a.

[0087] Each scanning line 3 a is arranged so as to oppose to thatchannel region 1 a′ of a semiconductor layer 1 a which is indicated by aregion of rightward rising hatches in the drawing, and it functions asthe gate electrode. In this manner, the pixel switching TFT 30 for whichthe scanning line 3 a is arranged as the gate electrode in opposition tothe channel region 1 a′ is disposed in each place where the scanningline 3 a and the data line 6 a intersect.

[0088] As shown in FIGS. 9 and 10, each storage capacitor 70 is formedin such a way that a relay layer 71 being the pixel potential sidecapacitance electrode which is connected to the heavily-doped drainregion 1 e of the TFT 30 and to the pixel electrode 9 a, and part of thecapacitance line 300 being the fixed potential side capacitanceelectrode are arranged in opposition to each other through a dielectricfilm 75.

[0089] When viewed in plan, each capacitance line 300 stretches in theshape of a stripe along the scanning line 3 a, and its part overlappingthe TFT 30 protrudes up and down in FIG. 9. Such a capacitance line 300should preferably be formed of, for example, a light-interceptingconductive film which contains a metal. When thus constructed, thecapacitance line 300 has, not only the function of the fixed potentialside capacitance electrode of the storage capacitor 70, but also thefunction of a light shield layer which shields the TFT 30 from incidentlight on the upper side of this TFT 30.

[0090] On the other hand, lower light shield films 11 a are disposed ina checkered pattern on the lower sides of the TFTs 30 over the TFT arraysubstrate 10. Each lower light shield film 11 a is made of, for example,a metal element, an alloy, a metal silicide or a polysilicide containingat least one of refractory metals, such as Ti (titanium), Cr (chromium),W (tungsten), Ta (tantalum) and Mo (molybdenum), or a stacked layer madeof such materials.

[0091] The data lines 6 a respectively extending in the verticaldirection in FIG. 9, and the capacitance lines 300 respectivelyextending in the lateral direction in FIG. 9 are formed intersectingwith each other, and the lower light shield films 11 a are formed in thecheckered pattern, whereby the non-aperture regions of the respectivepixels are defined.

[0092] As shown in FIGS. 9 and 10, each data line 6 a is electricallyconnected through a contact hole 81 to the heavily-doped source region 1d of the semiconductor layer 1 a which is made of, for example, apoly-silicon film. Incidentally, a relay layer made of the same film asthat of the above relay layer 71 may well be formed so as toelectrically connect the data line 6 a and the heavily-doped sourceregion 1 d through that relay layer as well as two contact holes.

[0093] It is favorable that each capacitance line 300 is extended fromthe image display area 10 a (refer to FIG. 6) where the pixel electrodes9 a are arranged, to the surroundings thereof, and that it iselectrically connected with a constant potential source so as to be heldat a fixed potential. Such a constant potential source may be theconstant potential source of a positive supply voltage or negativesupply voltage which is fed to the data line driver circuit or scanningline driver circuits, or it may be a constant potential which is fed tothe counterelectrode 21 of the microlens array plate 20. Further, eachlower light shield film 11 a disposed under the TFT 30 may be extendedfrom the image display area 10 a to the surroundings thereof andconnected to a constant potential source likewise to the capacitanceline 300, in order to reduce or prevent the potential fluctuation ofthis film 11 a from affecting the TFT 30 adversely.

[0094] Each pixel electrode 9 a is relayed by the relay layer 71,thereby to be electrically connected to the heavily-doped drain region 1e of the semiconductor layer 1 a through contact holes 83 and 85.

[0095] In FIGS. 9 and 10, the electrooptic device includes thetransparent TFT array substrate 10, and the microlens array plate 20(refer to FIGS. 1 through 4) which is arranged in opposition to thesubstrate 10. The TFT array substrate 10 is made of, for example, aquartz substrate, a glass substrate or a silicon substrate.

[0096] As shown in FIG. 10, the TFT array substrate 10 is provided witheach pixel electrode 9 a, which is overlaid with an orientation film 16subjected to a predetermined orientation treatment such as rubbing. Thepixel electrode 9 a is made of a transparent conductive film, forexample, ITO film. The orientation film 16 is made of a transparentorganic film, for example, polyimide film.

[0097] On the other hand, the microlens array plate 20 is provided withthe counterelectrode 21 over the whole area thereof, and thecounterelectrode 21 is underlaid with an orientation film 22 subjectedto a predetermined orientation treatment such as rubbing. Thecounterelectrode 21 is made of a transparent conductive film, forexample, ITO film. Besides, the orientation film 22 is made of atransparent organic film, such as polyimide film.

[0098] The microlens array plate 20 may well be provided with lightshield films 240 of checkered pattern or striped shape in correspondencewith the non-aperture regions of the respective pixels as shown in FIG.5. When such a construction is adopted, incident light from the side ofthe microlens array plate 20 can be more reliably hindered from enteringthe channel region 1 a′ and a lightly-doped source region 1 b as well asa lightly-doped drain region 1 c, by each light shield film 240 over themicrolens array plate 20 together with the capacitance line 300 and thedata line 6 a which define the non-aperture region as stated before.

[0099] A liquid crystal which is one example of the electroopticsubstance is enclosed between the TFT array substrate 10 and themicrolens array plate 20 which are thus constructed and which arearranged with the pixel electrodes 9 a and the counterelectrode 21facing to each other, and in a space surrounded with a sealant 52 (referto FIGS. 6 and 7), whereby a liquid crystal layer 50 is formed.

[0100] Further, a subbing insulating film 12 is provided under the pixelswitching TFTs 30. The subbing insulating film 12 has the function ofinsulating each TFT 30 from the lower light shield film 11 a for theinter-layer insulation. Besides, since the subbing insulating film 12 isformed over the whole area of the TFT array substrate 10, it has thefunction of preventing the characteristics of the pixel switching TFTs30 from changing due to the roughness of the TFT array substrate 10 inthe surface polishing thereof, the dirt of the TFT array substrate 10remaining after the wash thereof, etc.

[0101] Referring to FIG. 10, each pixel switching TFT 30 has an LDD(Lightly Doped Drain) structure. It is constituted by the scanning line3 a, that channel region 1 a′ of the semiconductor layer 1 a in which achannel is formed by an electric field from the scanning line 3 a, aninsulating film 2 which includes a gate insulating film insulating thescanning line 3 a and the semiconductor layer 1 a, the lightly-dopedsource region 1 b as well as the lightly-doped drain region 1 c of thesemiconductor layer 1 a, and the heavily-doped source region 1 d as wellas the heavily-doped drain region 1 e of the semiconductor layer 1 a.

[0102] Formed on the scanning line 3 a is a first inter-layer insulatingfilm 41 in which the contact hole 81 leading to the heavily-doped sourceregion 1 d, and the contact hole 83 leading to the heavily-doped drainregion 1 e are respectively provided.

[0103] The first inter-layer insulating film 41 is overlaid with therelay layer 71 and the capacitance line 300, which are overlaid with asecond inter-layer insulating film 42 where the contact hole 81 leadingto the heavily-doped source region 1 d and the contact hole 85 leadingto the relay layer 71 are respectively provided.

[0104] The data line 6 a is formed on the second inter-layer insulatingfilm 42, and they are overlaid with a third inter-layer insulating film43 which is flattened and which is formed with the contact hole 85leading to the relay layer 71. The pixel electrodes 9 a are provided onthe upper surface of the third inter-layer insulating film 43 thusconstructed.

[0105] In this exemplary embodiment, the surface of the thirdinter-layer insulating film 43 has been flattened by a CMP (ChemicalMechanical Polishing) treatment or the like, thereby to lessen theorientation defects of the liquid crystal in the liquid crystal layer 50as are caused by stepped parts ascribable to the various wiring linesand elements existing under this film 43.

[0106] The light collecting function of the microlens array plate 20 inthe electrooptic device is described below with reference to FIG. 11.FIG. 11 is a sectional view schematically showing a situation whereincident light rays are collected by each microlenses 500 of themicrolens array plate 20 used as the opposite substrate. By the way, inFIG. 11, each microlens 500 is arranged so as to be coaxial with thecorresponding pixel.

[0107] As shown in FIG. 11, the microlens array plate 20 includes theplurality of microlenses 500 which are arranged in the form of a matrixand by which the incident light rays entered from above as viewed in thefigure are collected onto the respectively corresponding pixelelectrodes 9 a, and the reflective film 220 which is formed at the edgepart of each lens. Besides, the counterelectrode 21 and the orientationfilm 22 are formed on the transparent plate member 210 (on the lowerside as viewed in the figure).

[0108] Due to the construction as described above, according to theelectrooptic device of this exemplary embodiment, the incident lightrays from the side of the microlens array plate 20 are collected ontothe respectively corresponding pixel electrodes 9 a by the plurality ofmicrolenses 500. Accordingly, an effective opening rate in each pixel isheightened more than in a case where the microlens 500 is not existent,or in a case where the reflective film 220 is not existent at the edgepart of the microlens 500.

[0109] In this exemplary embodiment, each microlens 500 especially has anon-spherical surface, and it exhibits an excellent lens efficiency anda slight spherical aberration. Therefore, the utilization efficiency ofthe incident light rays is very high.

[0110] In each of the exemplary embodiments described with reference toFIGS. 1 through 11 in the above, the data line driver circuit 101 andthe scanning line driver circuits 104 are disposed on the TFT arraysubstrate 10, but they may alternatively be electrically andmechanically connected to a driving LSI which is mounted on, forexample, a TAB (Tape Automated Bonding) substrate, through ananisotropic conductive film which is disposed at the peripheral part ofthe TFT array substrate 10. Besides, a polarization film, a phasedifference film, a polarizing plate, etc. are arranged in predetermineddirections on each that side of the microlens array plate 20 from whichprojected light enters, and on that side of the TFT array substrate 10from which exit light emerges, in accordance with, for example,operation modes such as a TN (Twisted Nematic) mode, a VA (VerticallyAligned) mode and a PDLC (Polymer Dispersed Liquid Crystal) mode, andeither of a normally white mode and a normally black mode.

[0111] In the exemplary embodiment shown in FIGS. 6 through 11, themicrolens array plate 20 as shown in FIGS. 1 through 4 is employed asthe opposite substrate, but it is also possible to utilize such amicrolens array plate 20 as the TFT array substrate 10. Alternatively,it is possible to mount the microlens array substrate 20 on the side ofthe TFT array substrate 10, in such a way that a glass substrate or thelike which is simply formed with a counterelectrode and an orientationfilm (not the microlens array plate 20) is used as the oppositesubstrate. That is, the structure of the present invention (refer toFIGS. 1 through 4) including the microlenses, the reflective film at theedge parts of the lenses, and the light shield films can be formed ormounted on the side of the TFT array substrate 10.

[0112] The present invention is also applicable to other electroopticdevices such as an electroluminescent device and an electrophoreticdevice.

[0113] (Method of Manufacturing Microlens array plate)

[0114] Next, a method of manufacturing a microlens array plate 20according to this exemplary embodiment is described below with referenceto FIGS. 12(a)-12(f).

[0115] First, as shown in FIG. 12(a), a transparent plate member 210 amade of quartz or the like is overlaid with a first film 220′ theetching rate of which for a predetermined kind of etchant, for example,one of hydrofluoric acid type is higher than that of the transparentplate member 210 a. Such a first film 220′ is formed of a transparentsilicon oxide film by, for example, CVD or sputtering. Thereafter, thefirst film 220′ is subjected to a heat treatment or annealing at apredetermined temperature of, for example, about 800-900° C. so as to bebaked, thereby to control its etching rate. On this occasion, thetransparent plate member 210 is made of, for example, quartz, and hence,such a problem as the destruction of the transparent plate member 210 adoes not especially occur in spite of such a heat treatment at thecomparatively high temperature.

[0116] At the subsequent step, a mask layer 612 is formed of apoly-silicon film on the first film 220′ by, for example, CVD orsputtering.

[0117] Subsequently, as shown in FIG. 12(b), pits 612 a are provided atpositions corresponding to the centers of microlenses to-be-formed, bypatterning which employs photolithography and etching for the mask 612.On this occasion, each pit 612 a is provided so that its diameter maybecome small as compared with the diameter of each microlens 500to-be-formed. Subsequently, as shown in FIG. 12(c), the first film 220′and the transparent plate member 210 a are wet-etched with an etchant ofhydrofluoric acid type, or the like through the mask 612 which isprovided with such pits 612 a. Then, the first film 220′ is etchedfaster because the etching rate of this first film 220′ for the etchantis higher than that of the transparent plate member 210 a. Morespecifically, before the etching penetrates through the first film 220′,spherical recesses are excavated in the parts of the first film 220′around the pits 612 a by the wet etching which has no directionality,but after the penetration, the first film 220′ is etched faster.Therefore, the etching spreads sidewards faster than in the depthwisedirection of the pits 612 a, that is, side etching proceeds relativelymuch, so that recesses 220 a each being in the shape of a pan of shallowbottom are excavated around the pits 612 a.

[0118] Thereafter, as shown in FIG. 12(d), the etching is ended at astage where recesses each of which has a size corresponding to themicrolens 500 have been excavated by a time period control or the like.That is, the transparent plate member 210 in which the recess in theshape of a shallow-bottomed pan is excavated every microlens iscompleted. Thus, there is obtained a structure which is peculiar to thepresent invention and in which a first film 220 is left in the vicinityof the edge of each recess and on the upper surface of the transparentplate member 210.

[0119] In this exemplary embodiment, the etching rate is especiallycontrolled by condition setting which concerns at least one of the sortof the first film 220′ relating to, for example, a substance, a densityand a porosity; the method of forming the first film 220′, for example,the CVD or the sputtering; a temperature for forming the first film220′, for example, one below about 400° C. or one of about 400-1000° C.;and the temperature of the heat treatment or the annealing after theformation of the first film 220′. By way of example, regarding the CVDand the sputtering, the latter densifies the first film 220′ more andcan make the etching rate thereof higher. Also, regarding the heattreatment after the formation of the first film 220′, when thetemperature is heightened, the first film 220′ is densified more, andthe etching rate thereof can be lowered, and conversely, when thetemperature is lowered, the etching rate of the first film 220′ can beheightened. Due to such a control of the etching rate, a curvature or acurvature distribution in a non-spherical surface which each recess tobe finally obtained defines can be controlled comparatively easily.

[0120] The curvature or the curvature distribution in the non-sphericalsurface which each recess to be finally obtained defines can also becontrolled by the thickness of the first film 220′.

[0121] The several conditions of controlling the etching rate and thethickness of the first film 220′ as stated above may be individually andconcretely set by an experimental, empirical, theoretical or the likeapproach or by a simulation, in accordance with the size of eachmicrolens 500 to be actually employed, a performance required of themicrolens 500, the specifications of a device, and so forth.

[0122] Subsequently, as shown in FIG. 12(e), the mask layer 612 isremoved by an etching process. The step of FIG. 12(e) can be dispensedwith when the thickness of the mask 612 is set so that this mask layer612 may be completely removed by the etching at the step of FIG. 12(d).

[0123] Subsequently, as shown in FIG. 12(f), the surfaces of themicrolenses 500 is coated with a thermosetting transparent adhesive, anda cover glass 200 made of Neoceram (trade name), quartz or the like ispressed against the adhesive so as to harden this adhesive. Thus, themicrolens 500 is finished up which is so constructed that each recessexcavated in the transparent plate member 210 is filled up with abonding layer 230. On this occasion, the non-spherical microlenses 500each of which is made up of a convex lens can be fabricatedcomparatively easily by forming the bonding layers 230 the refractivityof which is higher than that of the transparent plate member 210.

[0124] At the step shown in FIG. 12(f), the cover glass 200 may well bepolished so as to have a desired thickness.

[0125] As described above, according to the manufacturing method of thisexemplary embodiment, the microlens array plate 20 in which thenon-spherical microlenses 500, as shown in FIGS. 1 through 4, are formedin the shape of an array can be manufactured comparatively efficiently.

[0126] Besides, microlenses of biconvex lenses can be manufactured insuch a way that the transparent plate members 210 at the stage where therecesses shown in FIG. 12(e) have been completed are prepared in thenumber of two, and that they are stuck to each other. Alternatively,non-spherical microlenses can be manufactured in such a way that therecesses shown in FIG. 12(e) are utilized as a mold in the 2 P method orthe like.

[0127] In addition, in case of manufacturing the microlens array platein the modification shown in FIG. 5, the light shield films 240 and theprotective film 241 and the like may be formed in this order bysputtering, coating or the like, subsequently to the above step shown inFIG. 12(f).

[0128] (Exemplary Embodiment of Electronic equipment)

[0129] Next, an exemplary embodiment of a multiple-plate type colorprojector that is a practicable example of electronic equipment, inwhich the electrooptic device explained above in detail is employed as alight valve, is described below concerning the entire constructionthereof, particularly the optical construction thereof. FIG. 13 is aschematic sectional view of the multiple-plate type color projector.

[0130] Referring to FIG. 13, a liquid crystal projector 1100 which isone example of the multiple-plate type color projector in this exemplaryembodiment is constructed as a projector in which three liquid-crystalmodules each of which includes the electrooptic device having the drivercircuits mounted on the TFT array substrate are prepared and arerespectively employed as light valves 100R, 100G and 100B for colorsRGB.

[0131] In the liquid crystal projector 1100, when projection light isemitted from a lamp unit 1102 having a white light source such as metalhalide lamp, it is decomposed into light components R, G and Brespectively corresponding to the three primary colors RGB, by threemirrors 1106 and two dichroic mirrors 1108, and the light components R,G and B are respectively guided to the light valves 100R, 100G and 100Bof the corresponding colors. On this occasion, in order to prevent alight loss ascribable to a long optical path, the light B is especiallyguided through a relay lens system 1121 which consists of an entrancelens 1122, a relay lens 1123 and an exit lens 1124. Besides, the lightcomponents corresponding to the three primary colors, respectivelymodulated by the light valves 100R, 100G and 100B are composed again bya dichroic prism 1112. Thereafter, the resulting composed light isprojected as a color image on a screen 1120 through a projection lensassembly 1114.

[0132] The present invention is not restricted to the exemplaryembodiments stated above, but it shall be appropriately alterable withina scope not departing from the purport or idea of the invention readfrom the claims and the entire specification. A method of manufacturinga microlens, a microlens, an electrooptic device and an electronicequipment accompanied by such alterations shall also be covered withinthe technical scope of the present invention.

What is claimed is:
 1. A method of manufacturing a microlens,comprising: forming on a substrate a first film having an etching ratefor a predetermined kind of etchant that differs from an etching rate ofthe substrate; forming on the first film a mask in which a pit isprovided at a position corresponding to a center of the microlensto-be-formed; and performing wet etching through the mask to therebyexcavate in the substrate a non-spherical recess which defines a curvedsurface of the microlens.
 2. The method of manufacturing a microlensaccording to claim 1, the first film being higher in the etching ratethan the substrate.
 3. The method of manufacturing a microlens accordingto claim 1, further including: forming the substrate of a transparentsubstrate; and putting into the recess a transparent medium which has arefractivity higher than a refractivity of the transparent substrate. 4.The method of manufacturing a microlens according to claim 1, furtherincluding: forming the first film of at least one of a transparent filmand an opaque film.
 5. The method of manufacturing a microlens accordingto claim 1, further including: forming the first film of at least one ofa silicon oxide film and a silicon nitride film.
 6. The method ofmanufacturing a microlens according to claim 1, further including:controlling the etching rate by condition setting which concern at leastone of a sort of the first film, forming the first film, a condition toform the first film, and a temperature of a heat treatment after theformation of the first film.
 7. The method of manufacturing a microlensaccording to claim 1, further including: forming the mask of at leastone of a poly-silicon film, an amorphous silicon film and a hydrofluoricacid-proof film.
 8. The method of manufacturing a microlens according toclaim 1, further including: forming a plurality of such microlenses in ashape of an array on the substrate.
 9. A microlens manufactured by themethod of claim
 1. 10. An electrooptic device, comprising: the microlensof claim 9; a displaying electrode opposing the microlens; and at leastone of a wiring line and an electronic element connected to thedisplaying electrode.
 11. An electronic equipment, comprising: theelectrooptic device of claim
 10. 12. A microlens array plate,comprising: a plurality of microlenses, a cross-sectional shape of eachof the microlenses being semi-elliptical; a transparent member havingconcavities that define bottoms of the microlenses; a film formed on thetransparent member, and having pits that are formed in correspondencewith the concavities and that define edges of the microlenses; and acover member formed on said film.
 13. The microlens array plateaccording to claim 12, a cross-sectional shape in the vicinity of aregion featuring an angle of 50-60 degrees, which a tangential line to alens surface in the film forms with respect to a tangential line to anedge of a lens surface defined by the transparent member, beingsemielliptical.
 14. The microlens array plate according to claim 12, across-sectional shape of the lens surface in the film being rectilinear.15. An electrooptic device, comprising: the microlens array substrate ofclaim 12; displaying electrodes opposing the microlenses; and at leastone of wiring lines and electronic elements connected to the displayingelectrodes.
 16. An electronic equipment, comprising: the electroopticdevice of claim 15.